Magnetic clutch



Sept. 29, 1936. HOPE MAGNETIC CLUTCH Filed April 3, 1935 II /Iii ATTORNEY Patented Sept. 29, 1936 UlTED STATES PATENT OFFICE MAGNETIC CLUTCH James L. Hope, Milwaukee, Win. assignor to Dings Magnetic Separator Company, Milwaukee, Wis., a corporation of Wisconsin Application April 3, 1935. Serial No. 14,448 14 C. (01. 192-84) This invention relates in general to improve- Still another specific object of the invention is lnents in the art or connecting and disconnectto provide a positive clutch structure wherein mg adjoining rotary members, and relates more the gripping teeth may be located relatively close specifically to improved magnetic clutch rncchto the axis of rotation so as to reduce the periphd anisrn for drivingly interconnecting substantially oral speed thereof to a minimum. a allned rotary shafts and for effecting release oi An additional specific object of the invention the driving connection. is to provide an improved mounting for the mov- Generally defined, an object the present inable member of a releasable shaft coupling so vention is to provide improved magnetic clutch as to facilitate actuation of the mechanism, while ii mechanism which is durable in. construction, and retaining maxiurn strength. in which is moreover highly emclent in operation. Another specific object of the invention is to It has heretofore been proposed as shown and P o e a S p e an fl l magnetic clutch described in my prior Patent No. 1,989,934, grantassemblage which may be readily constructed and ed February 5, 1935, to provide a magnetic couconveniently manipulated.

15 pling comprising a pair of rotary coupling mem- These and other objects and advantages will 15 hers relatively movable along an axis and having be apparent lroni the iollowing detailed descripinter-engagealole teeth which are brought into tion. driving engagement with each other by an elec- A clear conception of embodiments of the imtromagnetic coil, and are disengaged by springs p ed lectures. d 0f e mode of Constructgo acting in opposition to the magnetic force. While ing and operating several types of magnetic this patented coupling has proven highly satisclutches built in accordance with the present iniactory in. general commercial use, it has been vention, may be had by referring to the drawing found under some conditions of operation, that accompanying and forming a part oi this specifithe interlocking teeth which were formed 01 magcation in which like reference characters desiggs netic material and were to some extent subjected mate the same or similar parts in the various directly to the magnetic influence, would not reviews. lease as quickly as desired. In clutches operat- Fig. l. is a part sectional side view of one type log at high speed there is also a tendency on of the improved magnetic clutch having one form the part or the electromagnetic coil to shift about or interlockable teeth formed on coactlng memco the axis of rotation due to inertia; and by virtue hers disposed outwardly beyond the magnet; of the fact that the driving teeth of these prior Fig. 2 is a part sectional end view of the clutch clutch mechanisms were located remote from the mechanism of Fi 1;

axis of rotation, the peripheral speed became ex- Fig. 3 is a. fragmentary development of the incessive in high speed drives. teriockable members of the clutch of Figs. 1 and 2; The present invention contemplates the provi- Fig. 4 is a fragmentary central longitudinal 35 sion of various improvements for obviating these section through another type of the improved objectionable features of the patented magnetic magnetic clutch; coupling, in a simple and most efiective manner. Fig. 5 is a fragmentary transverse section Due oi the more specific objects of the present through the clutch of Figure 4, taken along the invention is to provide an improved coupling line H; and wherein the toothed interlockable portions of the Fig. 6 is a part sectional fragmentary developdrlving and driven members are located outside ment of the interlockable members of the clutch of the magnetic field portion having maximum of Figs. 4 and 5, taken along the line 6-4; of intensity, thereby permitting most eiIective utl- Fig. 4. i5 lization of the actuating forces. While the improved features have been shown Another specific object of the invention is to and described as being applied to a specific type provide a magnetic clutch having inter-lockable or magnetic clutch for connecting the adjacent toothed members one or which is formed of nonends of alined rotary shafts, it is not the intent magnetic material in order to insure quick release to thereby unnecessarily restrict the scope. W of the interlock when the magnet is de-energized. Referring to Figs. 1, 2 and 3 of the drawing.

A further specific object oi the invention is to the improved magnetic clutch shown therein, provide an improved coil structure for electrocomprises in general a pair of hub elements 3, c magnetic couplings or the like, and simple means rigidly but adjustably secured to the adjacent 4 for preventing undesirable displacement of the ends of substantially alined rotary shafts in, il coil due to inertia. respectively; an electromagnetic coil l2 confined 55 within and cooperating with a magnet I9 which is fixedly but removably attached to the hub element 8 by means of cap screws I4; a magnetic toothed member I5 movably supported upon the other hub element 9 and having an annular series of end teeth I6 near the periphery thereof; a non-magnetic toothed member I l fixedly but removably attached to the periphery of the magnet I 3 and having an annular series 01." end toothed member I5 movably supported upon the teeth I8 adapted to interlock with the teeth 18. of the member I5; and an annular bearing block I9 also carried by the magnet I3 and coacting with a plane end surface of the hub element 9.

The'hub elements 8, 9 may be secured to the shafts I 0, ii inany suitable manner, and the coil I2 is preferably of substantially annular but slightly elliptical shape as shown in Fig. 5. This coil I2 is confined within a similarly elliptical groove formed in a casing 20 which is fitted within an annular side recess in the magnet I3, and has local end lugs 2| which are normally held in sockets in the magnet I3 by screws 22. The elliptical formation of the coil I2 positively prevents rotation thereof relative to its confining casing 20, and the lugs 2| likewise positively prevent rotation of the casing 20 relative to the magnet I3, but the coil I2 and its casing 20 may be readily removed from the magnet recess upon release of the screws 22. The electromagnetic coil I2 is connected to contact rings 23 carried by the hub element 8 within a suitable stationary housing 24, in a manner similar to that shown in my prior Patent No. 1,989,984, and brushes 25 coacting with these rings 23 within the housing 24 serve to energize the coil while the clutch mechanism is rotating.

The annular magnetic toothed member I5 is disposed within an end recess 28 in the hub element 9 and is cooperable with the annular poles of the ma et I3, spanning the recess in this magnet within which the coil I2 is disposed. The member I5 besides being provided with the radial teeth l5, has an annular series of peripheral gear teeth 21 which slidably engage an annular series of internal gear teeth 28 formed inteal with the element 9. The member I5 -normally coacts with and is urged against a buffer plate 29 located within the recess 26, by a series of compression springs 30, when the magnet I3 is de-energized, and is slidable along the teeth 28 away from the plate 29, when the magnet is energized thereby compressing the springs 30.

The corresponding ends of the springs 90 remote from the magnet l3, coact directly with the member I5 within sockets thereof, as shown in Fig. 1, and these springs embrace bolts 3| and have their opposite ends in engagement with the bolt heads. The bolts 3| pass through openings in the member I5 and plate 29, and are secured directly to the hub element 9, thereby cooperating with the teeth 21, 28 to provide a driving con nection between the element 9 and clutch member I5. v

The annular non-magnetic toothed member II snugly embraces the magnet I3 and is secured thereto in any suitable manner, as by one or more set screws 32, and the radial teeth I8 of the member I! are interlockable with the teeth I6 of the member I5 when the latter is drawn toward the magnet I3 by energization of the coil I2. The cooperating teeth I6, I8 are normally concealed and protected by an annular band 33 secured to the periphery of the element 9 and rotatable therewith. The annular bearing block I9 is mounted upon a ring support 34 secured directly to the magnet I8 inany suitable manner, and the interior of the magnet forms a chamber 35 which may be supplied with lubricant for the surface of coaction between the block i9 and the element 9. It is also to be noted, that lubricant which escapes from the bearing block I9, may flow under the influence of centrifugal force, through the .space between the member i5 and element 9, thereby lubricating the guiding surfaces between the bolts 3! and member i5 as well as the teeth 21?, 28.

5 Referring to Figs. 4, 5, and 6 of the drawing,

it will be noted that the embodiment of the invention shown therein is similar to that Just described, except for the location of the toothed interlockable clutch members and the formation of the teeth thereof. In the modification, the movable member I5 which is slidably supported by and rotatable with the hub element 9', has an annular series of radial end teeth I6 disposed near the axis of the shafts Ill, II; and these teeth 86' are interlockable with similarly shaped but reversed teeth l8 formed integral with the annular member I1 which is secured to the interior of the magnet I3 by means of keys. By virtue of this disposition of the teeth I8, I 8' near the axis-of rotation of the clutch, the annular bearing block I9 is located remote from the axis and is secured to the periphery of the magnet I3 by set screws 32. This bearing block I9" coacts with an end surface of the hub element 9' located near the clutch periphery Just within the protecting band 33, and the thrust bearing and teeth 21, 28 are again lubricated by centrifugal force from the chamber 95. The interlockable teeth I6, l8 of this modification are shown as being of slightly diiferent form than the teeth I6, I8 of Fig. 3, but may be of the same form if so desired.

While the normal operation of the improved clutch mechanisms should be apparent from the foregoing description of the details of construction, it will be noted, that when the cofl I2 is energized, the magnet ll quickly becomes e1- fective to compress the springs 30 and to draw the toothed member I5 toward the complementary toothed member I'l, thereby causing'the teeth I8, I8 to interlock and to produce a positive driving connection between the shafts l0, II. -When the magnetic coil I2 is de-energized, the springs 39 immediately become effective to disengage the teeth I6, I8, and such disengagement is extremely rapid by virtue of the fact that one of the toothed members is formed of nonmagnetic material. The intermeshing teeth 21, 29 permit free sliding of the member I5 relative to its carrying element 9 while providing a positive driving connection, and the thrust bearing block I9 prevents the elements 8, 9 from ap proaching each other axially when the electromagnetic force is applied. The normal operation of both types of clutches specifically illustrated, is obviously the same, and the structural differences do not afiect the operation.

By forming the coil I2 elliptical as shown in Fig. 5, and causing the same to coact with an elliptical housing 20, shifting of this coil due to inertia is positively prevented, even when the clutch mechanism is operated at high speed.

' While the clutch teeth I8, I8- may be formed as shown in Fig. 3, thereby providing relatively small increments or distances between the successive teeth which will permit almost immediate interlocking of these teeth, the form of teeth ill Eli

till

i6, i8 illustrated in Fig. 6, may be advantageous under certain conditions or operation. with the interlockable teeth located near the axis of rotation of the clutch, the peripheral speed thereof is also materially reduced, and such location may be desirable where high speed operation of the clutch prevails. The various bearing surfaces of the lubricated irom the chamber 35, with the aid of centrifugal tome and all portions of the clutch mechanism are conveniently accessible tor inspectlon and replacement. The coil l2 and its housing in may be ireely withdrawn from the recess in the magnet l3, by merely releasing the screws 22, and the entire magnet may be removed irom its mounting element 8 by merely withdrawing the cap screws H. The toothed member it may be removed trom the hub element 9 upon withdrawal of the screws SI, and the member ill or bearing ring it may be removed from the magnet it upon release of the said screws 32.

From the foregoing description it will be apparent that the present invention provides a magnetic clutch structure which is simple and compact in construction and which is moreover highly efiective in use. The improved assemblage may be conveniently applied to driving and driven shafts which are substantially alined, and is euectively protected against damage during actual operation. The invention has proven highly successful in commercial operation, and has been found to materially improve the emciency oi the type of clutch shown in my prior patent, especially under certain conditions of use.

It should be understood that it is not desired to limit the invention to the exact details of construction and to the precise mode oi operation herein shown and described, for various modifications within the scope of the claims may occur to persons skilled in the art.

It is claimed and desired to secure by Letters Patent:--

i. In combination, a pair of coupling members rotatable about a common axis and relatively movable thereaiong, an electro-magnet constantiy rotatable with one of said members and operable to relatively move said members along said axis, said members having inter-engageable teeth and the teeth or" one of said members being formed entirely of non-magnetic material, and resilient means for disengaging said teeth when said electro-magnet is de-energized.

2. "in combination, a pair of coupling members rotatable about a common axis, one of said members being movable along said axis and the other being fixed against such movement, an electromagnet constantly rotatable with said fixed member and operable to move said other member along said axis, said members having interengageable teeth and the teeth of one of said members being formed entirely of non-magnetic material, and resilient means for disengaging said teeth when said electro-magnet is de-energized.

3. In combination, a pair of relatively movable coupling members rotatable about a common axis, an annular electro-magnet constantly rotatable with one of said members and operable to produce an annular magnetic field for relatively moving said members along said axis, said members having annular'series oi interengageable teeth disposed outside of said field and the teeth of one of said members being formed 01 non-magnetic material, and resilient means tor clutch may be readily disengaging said teeth when said electro-magnet is lie-energized.

4. In combination, a pair of relatively movable coupling members rotatable about a common axis and having inter-engageable end teeth radiating from said axis, an annular magnet tor relatively moving said members to inter-connect said teeth and having an annular recess, a coil for energizing said magnet confined within said recess, said coil extending around said axis and having an elliptical support confined within said recess, and means ior disengaging said teeth when said coil is de-energized.

5. In combination, a pair of relatively movable coupling members rotatable about a common axis and having interlockable parts, an annular magnet tor relatively moving said members to inter-connect said parts, a coil l'or energizing said magnet, said coil surrounding said axis and having an elliptical support l'or preventing rotation thereoi! relative to said magnet, and means for disengaging said parts when said coil is ole-energized.

t. In combination, a pair of relatively movable coupllng members, an annular magnet for relatively moving said members and having an annular recess in the side thereof, a coil support disposed within said recess and having end lugs fitting local pockets in said magnet, a coil tor energizing said magnet, said coll surrounding said axis and coacting with an elliptical surface of said support, and means for moving said members in opposition to said magnet.

"i. In combination, a pair of hub elements rotatable about an axis, a magnet carried by one of said hub elements and having a thrust bearing engaging an end surface of the other elements, a toothed member movably supported by said other element and movable along said axis by said magnet, a toothed member carried by said magnet and oooperable with said movable toothed member to produce a positive driving connection between said members, and means for moving said movable member away from said magnet.

8. In combination, a pair of hub elements rotatable about an axis, an annular magnet carried by one of said elements and surrounding said axis, a thrust bearing interposed between said magnet and said other element, a movable member carried by said other element and cooperable with said magnet, another member fixedly secured to said magnet, said movable and fixed members having interengageable teeth disposed beyond the zone of action of said magnet, and means for moving said movable member away from said magnet.

9. In combination, a pair of hub elements rotatable about an axis, an annular magnet carried by one of said elements and having a recess facing the other of said elements, a coil disposed within said recess and operable to energize said magnet, a movable member carried by said other element, and cooper-able with said magnet, another member flxedly secured to said magnet, said movable and fixed members having inter-engageable teeth adaptable to be brought into interlocking position by said magnet and said teeth being disposed beyond the zone of action of said magnet, and resilient means for urging said movable member away irom said magnet.

10. In combination, a pair of hub elements rotatable about a common. axis, a coupling member carried by each of said hub elements, one of said members being movable along said axis and the other being fixed against such movement, an electro-magnet constantly rotatable with said fixed member and operable to move said other member along said axis within its carrying element, said members having interengageable teeth, and said movable member having additional teeth slidable along complementary teeth of its carrying element, and resilient means for disengaging said member teeth when said electro-magnet is de-energized.

11. In combination, a pair of hub elements rotatable about a common axis, interlockable members carried by said hub elements, one of said members being formed with teeth which are slidable along complementary teeth on its carrying element and the other of said members being fixed against movement relative to its carrying element, an electro-magnet constantly rotatable with said fixed member and operable to move said other member along said axis, and resilient means for urging said movable member away from said fixed member.

, 12. In combination, a pair of coupling mem-- bers rotatable about a common axis and relatively movable therealong, an electro-magnet operable to relatively move said members along said axis.- said members having interengageable teeth and the teeth of one of said members being formed entirely oi non-magnetic material, andmeans ior disengaging said teeth when said electro-magnet is tie-energized.

13. In combination, a pair of coupling members rotatable about a common axis, one of said members being movable along said axis and the other being fixed against such movement, an electro-magnet operable to move said other member along said axis, said members having interengageable teeth and the teeth. of one of said members being formed entirely oi non-magnetic material, and means for disengaging said teeth when said electro-magnet is de-energized.

14. In combination, a pair of relatively movable coupling members rotatable about a common axis, an annular electro-magnet operable to produce an annular magnetic field for relatively moving said members along said axis, said members having annular series of inter-engageable teeth disposed outside of said field and the teeth of one of said members being formed of non-magnetic material, and means for disengaging said teeth when said electro-magnet is deenergized.

JAB/m8 L. HOPE. 

